Professional engineering expert witnesses may write reports and testify on issues involving engineering risk assessments, engineering document responsibility, registered professional engineers, and field engineering. In Consumer Guide to Professional Engineering and Professional Land Surveying, the California Board for Professional Engineers, Land Surveyors, and Geologists writes:
Professional engineers do not have a duty to supervise your project during construction. In general, the engineer draws the plans and the contractor does the construction. The engineer has no responsibility to supervise the contractor. If you wish to add construction supervision to the engineer’s duties, you will need to include this in your contract. Such supervision usually consists only of periodic oversight of the project.